IGF-BPs control the distribution, function and activity of IGFs in various cell tissues and body fluids. Currently, there are seven named IGF-BPs that form high affinity complexes with both IGF-I and IGF-II. IGF-BP5 is a 28.6 kDa, cysteine-rich, secreted protein produced by vascular smooth muscle cells. It is the major IGF-binding protein present in bone tissue and helps potentiate the action of IGF-I on smooth muscle cells, fibroblasts, and osteoblasts. Data shows that IGFBP-5 acts as a growth inhibitor and pro-apoptotic agent in breast cancer cells. IGFBP-5-overexpressing mice show an increase in neonatal mortality, reduced female fertility, whole-body growth inhibition, and retarded muscle development. Recombinant Human IGF-BP5 is a 28.6 kDa protein consisting of 253 amino acid residues.
Amino Acid Sequence
The ED 50 was determined by its ability to inhibit IGF-II induced proliferation of MCF-7 is 0.3 µg/ml in the presence of 15 ng/ml of human IGF-II.
Endotoxin level is <0.1 ng/μg of protein (<1EU/μg).
Centrifuge the vial prior to opening. Reconstitute in water to a concentration of 0.1–1.0 mg/ml. Do not vortex. For extended storage, it is recommended to further dilute in a buffer containing a carrier protein (example 0.1% BSA) and store in working aliquots at –20°C to –80°C.